Serhiy Grabarchuk is a famous Ukrainian puzzle designer who lives in Uzhgorod.
The puzzle depicted on the piece of drawing that he sent looked like a strange adornment weaved into a "coiffure" design.
If you put a glass carefully onto the completing puzzle, it becomes, indeed, a coaster.
Using this when serving drinks to guests will on doubt create stimulating conversation.
The theme is "coiffure."